Question

which element has the largest ionization energy in each pair? 1. sodium or potassium? 2. magnesium or phosphorus? 3. magnesium or barium? 4. carbon or fluorine?

Explanation:

Step1: Recall ionization - energy trend

Ionization energy increases across a period and decreases down a group.

Step2: Compare sodium and potassium

Sodium (Na) is in period 3 and potassium (K) is in period 4. Since ionization - energy decreases down a group, sodium has a larger ionization energy.

Step3: Compare magnesium and phosphorus

Magnesium (Mg) is in group 2 and phosphorus (P) is in group 15. Across a period, ionization energy generally increases. Phosphorus has a larger ionization energy as it is further to the right in the same period.

Step4: Compare magnesium and barium

Magnesium is in period 3 and barium (Ba) is in period 6. Since ionization - energy decreases down a group, magnesium has a larger ionization energy.

Step5: Compare carbon and fluorine

Carbon (C) is in group 14 and fluorine (F) is in group 17. Across a period, ionization energy increases. Fluorine has a larger ionization energy as it is further to the right in the same period.

Answer:

1. Sodium
2. Phosphorus
3. Magnesium
4. Fluorine